diff --git a/compiler-rt/lib/asan/asan_poisoning.h b/compiler-rt/lib/asan/asan_poisoning.h
--- a/compiler-rt/lib/asan/asan_poisoning.h
+++ b/compiler-rt/lib/asan/asan_poisoning.h
@@ -15,6 +15,7 @@
 #include "asan_internal.h"
 #include "asan_mapping.h"
 #include "sanitizer_common/sanitizer_flags.h"
+#include "sanitizer_common/sanitizer_linux.h"
 #include "sanitizer_common/sanitizer_platform.h"
 
 namespace __asan {
@@ -67,7 +68,15 @@
       if (page_end != shadow_end) {
         REAL(memset)((void *)page_end, 0, shadow_end - page_end);
       }
-      ReserveShadowMemoryRange(page_beg, page_end - 1, nullptr);
+#  ifdef SANITIZER_LINUX
+      // MADV_DONTNEED is not guaranteed to succeed. In particular it fails
+      // on locked pages. We never lock any shadow pages ourselves, but let's
+      // not assume that the user would never attempt to lock the entire process
+      // (e.g. using mlockall). However, if it does succeed, we are guaranteed
+      // that future accesses will be zero'd.
+      if (ReleaseMemoryPagesToOSAndZeroFill(page_beg, page_end) != 0)
+#  endif
+        ReserveShadowMemoryRange(page_beg, page_end - 1, nullptr);
     }
   }
 #endif // SANITIZER_FUCHSIA
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_linux.h b/compiler-rt/lib/sanitizer_common/sanitizer_linux.h
--- a/compiler-rt/lib/sanitizer_common/sanitizer_linux.h
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_linux.h
@@ -126,13 +126,8 @@
 // Releases memory pages entirely within the [beg, end] address range.
 // The pages no longer count toward RSS; reads are guaranteed to return 0.
 // Requires (but does not verify!) that pages are MAP_PRIVATE.
-inline void ReleaseMemoryPagesToOSAndZeroFill(uptr beg, uptr end) {
-  // man madvise on Linux promises zero-fill for anonymous private pages.
-  // Testing shows the same behaviour for private (but not anonymous) mappings
-  // of shm_open() files, as long as the underlying file is untouched.
-  CHECK(SANITIZER_LINUX);
-  ReleaseMemoryPagesToOS(beg, end);
-}
+// Returns 0 on success, -1 on error.
+int ReleaseMemoryPagesToOSAndZeroFill(uptr beg, uptr end);
 
 #if SANITIZER_ANDROID
 
diff --git a/compiler-rt/lib/sanitizer_common/sanitizer_linux.cpp b/compiler-rt/lib/sanitizer_common/sanitizer_linux.cpp
--- a/compiler-rt/lib/sanitizer_common/sanitizer_linux.cpp
+++ b/compiler-rt/lib/sanitizer_common/sanitizer_linux.cpp
@@ -2374,6 +2374,22 @@
   return true;
 }
 
+int ReleaseMemoryPagesToOSAndZeroFill(uptr beg, uptr end) {
+  // man madvise on Linux promises zero-fill for anonymous private pages.
+  // Testing shows the same behaviour for private (but not anonymous) mappings
+  // of shm_open() files, as long as the underlying file is untouched.
+  CHECK(SANITIZER_LINUX);
+  // This is the same as ReleaseMemoryPagesToOS, but with additional error
+  // handling.
+  uptr page_size = GetPageSizeCached();
+  uptr beg_aligned = RoundUpTo(beg, page_size);
+  uptr end_aligned = RoundDownTo(end, page_size);
+  if (beg_aligned < end_aligned)
+    return internal_madvise(beg_aligned, end_aligned - beg_aligned,
+                            SANITIZER_MADVISE_DONTNEED);
+  return 0;
+}
+
 } // namespace __sanitizer
 
 #endif